Devel::Events::Generator::Objects(3)

NAME
Devel::Events::Generator::Objects - Generate events for "bless"ing and destruction of objects.

SYNOPSIS
        use Devel::Events::Generator::Objects; # must be loaded before any code you want to instrument

        my $g = Devel::Events::Generator::Objects->new(
                handler => $h,
        );

        $g->enable(); # only one Objects generator may be enabled at a time

        $code->(); # objects being created and destroyed cause events to be generated

        $g->disable();

DESCRIPTION
This module overrides "CORE::GLOBAL::bless" on load. The altered version will delegate back to the original version until an instance of a generator is enabled.

When a generator is enabled (only one Devel::Events::Generator::Objects instance may be enabled at a time. Use Devel::Events::Handler::Multiplex to dup events to multiple listeners), the overridden version of "bless" will cause an "object_bless" event to fire, and will also attach magic to the object to keep track of it's destruction using Variable::Magic.

When the object is freed by the interpreter an "object_destroy" event is fired. Unfortunately by this time "perl" has already unblessed the object in question, so in order to keep track of the class you must associate it yourself with the reference address.

Devel::Events::Handler::ObjectTracker contains a detailed usage example.

EVENTS

object_bless
    When the generator is enabled, this event will fire on every call to "bless" for all code loaded after this module was loaded.

    In the future this event might omit objects created during event handling, but currently it does not.

    object
        The object that was blessed

    old_class
        If this is a rebless then this parameter contains the class the object was in just before the bless.

    package
    file
    line
        These fields correspond to the location o the call to "bless".

object_destroy
    For every object created while the generator was enabled, magic to track destruction will be attached. When the object is freed this magic callback will fire this event.

    object
        This field contains a reference to the object.

        NOTE: by the time this callback fires the object is no longer blessed. Be sure to keep track of the class of every refaddr as reported by "object_bless" in your handler if you need to know the class the object belonged to at destroy time..

METHODS

enable
    Make this instance the enabled one (disabling any other instance which is enabled).

    This only applies to the "object_bless" method.

disable
    Disable this instance. Will stop generating "object_bless" events.

bless
    The method called by the "CORE::GLOBAL::bless" hook.

    Uses "CORE::bless" to bless the data, and then calls "object_bless".

object_bless
    Generates the "object_bless" event.

    Calls "rack_object".

object_destroy
    Generates the "object_destroy" event.

    Calls "untrack_object".

tracker_magic
    A class method containing the Variable::Magic specification necessary for track_object to work.

track_object
    Attach magic to an object that will call "object_destroy" when the data is about to be freed.

untrack_object
    Currently empty. A subclass with a different implementation of "track_object" might want to override this.

SEE ALSO
Devel::Object::Leak, Variable::Magic